The collection of 120 dental, 13 salivary calculi and 250 samples of saliva were investigated by X-Ray diffraction, IR-spectroscopy. In this work the thermodynamic crystallization model of main minaral phases of dental and salivary calculi was build on the base of dates about quantitative and qualitative composition of saliva and plaque fluid. Also the experimental simulation of main mineral phase’s formation from saliva-like solution was made.